Weather resistant automatic meter reading unit

ABSTRACT

A chassis for a residential utility meter reading unit includes individual chambers including a transmitter chamber containing a printed circuit board, an indexing unit chamber containing the mechanism for operating dials that rotated in response to use of the utility product to indicate the magnitude of consumption, and a battery chamber releasably connected to the chassis and adapted to complete an electrical connection between batteries and circuit board as the third chamber moves relative to the chassis. A transparent cover overlaps a slot formed in the chassis and a leg extending from the battery chamber moveable in the slot. Rails on the chassis block movement of sliders on the battery pack away from the chassis to prevent disengagement of the battery chamber from the chassis unless the cover and its attachment screws are first removed.

[0001] This application claims the benefit under 35 USC 119(e) ofprovisional application No. 60/234,328, filed Sep. 22, 2000.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to the field of automatic meter readingunits, AMR units, particularly to such units having replaceable batterypacks.

[0004] 2. Brief Description of the Prior Art

[0005] Currently, the most common method used by utility providers todetermine the quantity of electricity, gas and water utility productused by a residential customer services is to read manually eachcustomers' meter. Most of the meters are mechanical. The flow ofelectricity, water or gas induces a disk to rotate. That rotation forcesa set of gears to scroll, which mechanically displays the usage. Thestaff reading the meters walks from residence to residence, writes downthe current consumption showing on the meter, and inputs the informationinto a billing computer, which generates the individual bills mailed tothe customers.

[0006] A network, a one way SSDS (spread spectrum direct sequence)network for minimizing the life cycle cost of the system, has beenproposed to provide a valid alternative to conventional meter readingand existing AMR technologies. That network consists of a large numberof transmitters connected to the meters, transmitting in SSDS packetsthe readings of the utility consumption; a network of SSDS receivers,each receiver monitoring tens of thousands of transmitters, obtainingthe transmitted data packets, compressing the SSDS modulation andstoring the data; and a network control center, which collects the datafrom the receivers via a dial-up line or any low cost communicationmeans, stores the data in protected database, and prepares it forbilling. The network transmitters use a single PCB design, a novel BPSKmodulator, low-cost frequency reference, and printed low cost antennaeincluding the matching circuits.

[0007] Residential meters, such as utility meters for use with such anetwork, operate with transmitters having batteries, which must bereplaced periodically. Water or moisture, which can produce corrosion,enter the meter box and reach the printed circuit board (PCB) locatedthere, is a problem associated with battery replacement. With thepresent invention, battery replacement is made faster and safer withoutwater penetration to the PCB or the metal contacts.

SUMMARY OF THE INVENTION

[0008] It is an object of this invention that the battery cells not beassembled in the same chamber with the printed circuit board or indexmechanism in order to prevent water entry to the area of the transmitterand index electronics during the process of replacing the batteries orwhile maintaining the index mechanism.

[0009] It is another object of this invention to provide a meter readingunit in which battery replacement requires removing the securing plasticseals, removing the screws holding a transparent front cover, replacingthe battery pack, reinstalling the screws and seals, and injectingsilicon grease to the electric contact seal to avoid corrosion.

[0010] It is yet another object of this invention that the battery packbe protected against any unauthorized access without first removing twofront plastic access seals, securing screws and a transparent cover toaccess the battery pack.

[0011] In realizing these objects and advantages a weather resistantautomatic meter reading unit according to this invention includes achassis divided into chambers; a first chamber containing a printedcircuit board having a first terminal for connection to an electricalpower source; and a second chamber sealed from the first chamber, sizedto contain and hold batteries, having a second terminal electricallyconnectable to the batteries, moveable relative to the chassis, adaptedto complete an electrical connection between the first terminal andsecond terminal as the second chamber moves relative to the firstchamber, and releasably fixed to the chassis.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Eighteen figures have been selected to illustrate a preferredembodiment of the invention.

[0013]FIG. 1 is a front view of a gas meter assembly having an automaticmeter reading unit installed.

[0014]FIG. 2 is a top front view of the assembly of FIG. 1.

[0015]FIG. 3 is a side view of the assembly of FIG. 1.

[0016]FIGS. 4 and 5 are isometric views of the assembly of FIGS. 1-3.

[0017]FIG. 6 is a photographic reproduction in perspective of theautomatic meter reading unit.

[0018]FIG. 7 is a front view of the automatic meter reading unit.

[0019]FIG. 8 is a cross section taken at plane 8-8 of FIG. 7.

[0020]FIG. 9 is a cross section taken at plane 9-9 of FIG. 7.

[0021]FIG. 10 is a cross section taken at plane 10-10 of FIG. 7.

[0022]FIG. 11 is a portion of the cross section shown in FIG. 9.

[0023]FIGS. 12 and 16 are isometric views of the battery pack portion ofthe automatic meter reading unit.

[0024]FIGS. 13, 14 and 15 are end, front and bottom views of the batterypack, respectively.

[0025]FIG. 17 is an isometric view of the battery pack case with thebatteries and end cover removed.

[0026]FIG. 18 is an isometric view of the battery pack showing springmetal contacts adjacent the box, the end cover, batteries and batterycase mutually spaced apart.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0027] Referring first to FIGS. 1-5, a residential utility meter readingunit 10 according to the present invention includes a box 12 containingmechanical components for producing an indication of the magnitude andrate of use of a utility product such as gas, water or electricity; atransmitter unit 14 mounted on the top of the box at its front; abattery pack 16 fixed to the transmitter unit; and an index mechanism 18located at the front face of the transmitter having a series of dials20, each having a rotating indicator pointing to a printed gradatedscale representing the amount of consumed product and the current rateof its use by the residential customer.

[0028]FIG. 6 shows the transmitter unit 14 having its transparent cover,face plate and attaching screws removed to expose the index mechanism18, which in this case is suited for use on a gas meter, and batterypack 16, removed from its slot 22 on the chassis front 24. In theassembled condition, the battery pack is guided for travel along slot 22by fitting sliders 26, 28, located at the upper and lower edges of thepack, into rails 30, 32, formed integrally on the upper and lower edgesof the chassis front. The battery pack is closed at its outer surface bya cover 34. Electric contact between the battery terminals and metalrivet contacts 36, 38, carried on the transmitter PCB, is completed whenthe leg 40 of the battery pack completes its travel to the lower, innerend of slot 22.

[0029] The battery pack 16 is completely sealed against moisture and theambient environment due to its enclosing cover 42, end cover 34 andsilicon grease, injected between the main enclosure of the chassis andbattery pack at the greaser point 44 (best seen in FIG. 7).

[0030] Referring next to FIGS. 7-11, the transmitter unit is enclosed byrear cover 46 and front cover 48, which covers overlap and are sealedmutually by a seal 49, preferably a glued room temperature vulcanizedrubber applied by a dispensing process in the manufacturing plant wherethe meter is assembled. A portion of the front cover defines a chamber50 occupied by the rotating indicators 20 and the gears 52 that drivethe indicators of the index mechanism 18. A transparent cover 54 coversthe face of the index mechanism, and a face plate 56, is secured to therear cover 46 by attachment screws 58-64. The cover 54 and face plate 56overlap the slot 22 into which the leg 40 of the battery pack isinserted, thereby securing the battery pack and preventing its removalexcept by removing two front plastic access seals, the screws andremoving the cover and face plate. The attachment screws 58-64 engagescrew threads formed in the rear cover 46.

[0031] The rear cover 46 is formed with multiple shoulders 64, and thefront cover 48 is formed with similar shoulders 66, adjacent and facingthe shoulders 64. Located between the shoulders 64 and 66 and held inposition on the shoulders, is the PCB 68 of the transmitter unit 14. ThePCB supports metal rivet contacts 36, 38, which electrically connect thebattery terminals to the PCB when the leg 40 of the battery pack 16 isfully inserted into the slot 22. A seal 70, fitted within a well 72 inthe front cover below the transparent cover 54, seals the index unit andtransmitter unit from the environment.

[0032]FIG. 8 shows two batteries cells 80, 82 standing upright in thebattery pack, which inn that figure is held in place in its operatingposition under the transparent cover 54. FIG. 18 shows two electriccontacts strips 84, 86 preferably formed of spring metal and located atthe lower end of the leg 40, each strip adapted to contact a metal rivetcontact 36, 38 on the PCB when the battery pack is fully inserted inslot 22, thereby completing an electric connection between the batterycells and the PCB. The PCB 68 is separated physically from the indexmechanism 18.

[0033] With the present invention, whenever it is necessary to replacethe battery cells, the replacement requires only removing the securingplastic seals, removing the screws holding the transparent front cover,replacing the battery pack, reinstalling the screws and seals, andinjecting silicon grease to the electric contact seal to avoidcorrosion.

[0034] Although the form of the invention shown and described hereconstitutes the preferred embodiment of the invention, it is notintended to illustrate all possible forms of the invention. Words usedhere are words of description rather than of limitation. Various changesin the form of the invention may be made without departing from thespirit and scope of the invention as disclosed.

I claim
 1. A weather resistant utility meter reading unit for producingan indication of the quantity of a utility product consumed, comprising:a chassis divided into chambers; a first chamber containing atransmitting unit including a printed circuit board having a contact forconnection to an electrical power source; a second chamber separate fromthe first chamber, containing an index unit having multiple rotatingindicators, each indicator pointing to a gradated scale representing theamount of consumed product, and closed by a removable cover; and a thirdchamber sealed from the first chamber, sized to contain and holdbatteries in a predetermined position therein, adapted for electricalconnection to the printed circuit board to provide a source of electricpower to said board, the third chamber releasably fixed to the chassis.2. The utility meter reading unit of claim 1, wherein the first chamberfurther comprises: a first cover having a first free edge around aperiphery of the first cover; second cover having a second free edgearound a periphery of the first cover, the second edge directed towardthe first cover and overlapping the first edge; and a seal locating in aspace overlapped by the first and second covers and located near thefirst and second edges.
 3. The utility meter reading unit of claim 2,wherein: the first cover is formed integrally with multiple firstshoulders located within the first cover; the second cover is formedintegrally with multiple second shoulders located within the secondcover, the second shoulders directed toward the first shoulders, a thinspace being created between the first and second shoulder; the printedcircuit board having first and second surfaces, said surfaces beinglocated between the first and second shoulders, whereby the printedcircuit board is held in position inside the first chamber.
 4. Theutility meter reading unit of claim 1, wherein: the chassis includes aslot extending to a first electric contact connected to the printedcircuit board; the third chamber includes a surface extending outwardtherefrom and sized to move within the slot, said surface carrying asecond electric contact connected to the batteries; a spring biasing thefirst and second electric contacts into mutual contact, whereby theprinted circuit board is electrically connected to the batteries; andthe removable cover overlaps the slot and said surface to releasablyhold the third chamber to the chassis.
 5. The utility meter reading unitof claim 1, wherein: the chassis includes a slot, first and second railshaving a surface for blocking movement relative to the chassis; furthercomprising a leg extending outward from the third chamber, moveablealong the slot, sliders fitted adjacent the blocking surfaces of therails, moveable along the rails and having a surface for contacting therails to prevent movement of the third chamber relative to the chassis;and attachment screws engageable with the chassis for connecting theremovable cover to the chassis; and wherein the removable cover overlapsthe slot and leg to prevent movement of the third chamber relative tothe chassis.
 6. The utility meter reading unit of claim 5, wherein: thechassis includes a slot extending to a first electric connection to theprinted circuit board, and first and second rails having a blockingsurface; further comprising a leg fixed to and extending outward fromthe third chamber, moveable along the slot, carrying a second electricconnection to the batteries, sliders located adjacent the blockingsurface of the rails, moveable along the rails, having a surface forcontacting the rails to prevent movement of the leg relative to thechassis; and attachment screws engageable with the chassis forconnecting the removable cover to the chassis; and wherein the removablecover overlaps the slot and leg to prevent movement of the leg relativeto the chassis.
 7. The utility meter reading unit of claim 6, furthercomprising: a spring urging completion of an electric connection betweenthe printed circuit board and batteries.
 8. A utility meter reading unitfor producing an indication of the quantity of a utility productconsumed, comprising: a chassis divided into chambers; a first chambercontaining a printed circuit board having a first terminal forconnection to an electrical power source; and a second chamber sized tocontain and hold batteries therein, having a second terminalelectrically connectable to the batteries, moveable relative to thechassis, adapted to complete an electrical connection between the firstterminal and second terminal as the second chamber moves relative to thefirst chamber, and releasably fixed to the chassis.
 9. The utility meterreading unit of claim 8, wherein the first chamber further comprises: afirst cover having a first free edge around a periphery of the firstcover; second cover having a second free edge around a periphery of thefirst cover, the second edge directed toward the first cover andoverlapping the first edge; and a seal locating in a space overlapped bythe first and second covers and located near the first and second edges.10. The utility meter reading unit of claim 9, wherein: the first coveris formed integrally with multiple first shoulders located within thefirst cover; the second cover is formed integrally with multiple secondshoulders located within the second cover, the second shoulders directedtoward the first shoulders, a thin space being created between the firstand second shoulder; the printed circuit board having first and secondsurfaces, said surfaces being located between the first and secondshoulders, whereby the printed circuit board is held in position insidethe first chamber.
 11. The utility meter reading unit of claim 9,wherein: the chassis includes a slot extending to a first electriccontact connected to the printed circuit board; the second chamberincludes a surface extending outward therefrom and sized to move withinthe slot, said surface carrying a second electric contact connected tothe batteries; a spring biasing the first and second electric contactsinto mutual contact, whereby the printed circuit board is electricallyconnected to the batteries; and the removable cover overlaps the slotand said surface to releasably hold the second chamber to the chassis.12. The utility meter reading unit of claim 8, wherein: the chassisincludes a slot, first and second rails having a surface for blockingmovement relative to the chassis; further comprising a leg extendingoutward from the second chamber, moveable along the slot, sliders fittedadjacent the blocking surfaces of the rails, moveable along the railsand having a surface for contacting the rails to prevent movement of thethird chamber relative to the chassis; and attachment screws engageablewith the chassis for connecting the removable cover to the chassis; andwherein the removable cover overlaps the slot and leg to preventmovement of the second chamber relative to the chassis.
 13. The utilitymeter reading unit of claim 12, wherein: the chassis includes a slotextending to a first electric connection to the printed circuit board,and first and second rails having a blocking surface; further comprisinga leg fixed to and extending outward from the third chamber, moveablealong the slot, carrying a second electric connection to the batteries,sliders located adjacent the blocking surface of the rails, moveablealong the rails, having a surface for contacting the rails to preventmovement of the leg relative to the chassis; and attachment screwsengageable with the chassis for connecting the removable cover to thechassis; and wherein the removable cover overlaps the slot and leg toprevent movement of the leg relative to the chassis.
 14. The utilitymeter reading unit of claim 13, further comprising: a spring urgingcompletion of an electric connection between the printed circuit boardand batteries.
 15. A utility meter reading unit for producing anindication of the quantity of a utility product consumed, comprising: achassis divided into chambers, including a slot extending along apredetermined direction, first and second rails directed along the slothaving a blocking surface preventing movement away from the slot; afirst chamber containing a printed circuit board having a first terminalfor connection to an electrical power source; a second chamber sized tocontain and hold batteries, including a leg extending into the slot, asecond terminal electrically connectable to the batteries and adapted tocomplete an electrical connection between the first terminal and secondterminal as the leg moves along the slot, sliders located adjacent theblocking surface having a surface for contacting the blocking surface toprevent movement of the leg away from the slot; a removable coveroverlapping the slot and leg to prevent movement of the leg out of theslot; and attachment screws engageable with the chassis for connectingthe removable cover to the chassis.